Anne Fernald must have had mixed feelings last year as the vocabulary debate peaked in education once more. Teachers were recognising the value of vocabulary and how it influenced education outcomes, and this has been her career’s focus. But the simplification of the debate, on occasion, as being about simply “recognising words” must have grated. She says there is much more to vocabulary than that - those words need to be understood in context, too

“Early differences in oral language skills are important because they predict later school success,” explains the American psychologist, who is currently based at Stanford University. “Those five-year-olds who know more words and are more fluent in understanding speech are much more likely to succeed in reading comprehension at age 8 and older, and thus are more likely to do well in school at every level. In contrast, their peers with smaller vocabularies and poor listening comprehension skills are likely to have ongoing difficulties in reading comprehension, and to do less well overall in school.”

But that word knowledge, she says, is not about simply recognising a word when you read it - you need to have a deep contextual knowledge of that word built up over time in the toddler years.

“They have to hear those words spoken over and over again in meaningful contexts. In this way, kids learn new words related to new concepts, building up knowledge as they gain in vocabulary. And as toddlers begin to find meaning in the words they hear, they get better and better at interpreting spoken language. They develop vocabulary and comprehension abilities entirely through listening to the language spoken to them in interactive contexts.”

If you do not have that experience, then school can fail to give you the help you need, Fernald argues. She says the term “learn to read” has two quite different meanings that are often confused. In the first sense, it refers to decoding; the process of converting written marks into sounds, and sounds into words. But in the second sense, reading refers to language comprehension; a fundamentally different process of interpreting words as meaningful and understanding information conveyed by strings of words in combination.

“A child may learn to read in the first sense, developing skill in sounding out familiar words,” Fernald says, “but this accomplishment in no way ensures that the child will be able to learn to read in the second sense, developing the ability to comprehend meaning in written text that includes unknown as well as known words. While skill in decoding is necessary for success in reading, it is far from sufficient. A monolingual English-speaking child who learns to sound out English words will also be able to sound out many words in Spanish, but with no understanding at all of what they mean.”

The trouble is, she says, early schooling has a strong focus on learning to decode words in simple texts, rather than learning new vocabulary. As they progress, pupils are expected to transition from learning to read to “reading to learn”. From this point, they are expected to gain new knowledge about all kinds of unfamiliar subjects, by reading challenging texts that include new words the child has never heard or seen before.

But, Fernald says, researchers have found that in order for children to be able to understand such texts, they need to know the meanings of 95 per cent of the words within them, and then use those familiar words to infer the meaning of the 5 per cent that they don’t know.

“Those children who already know 95 per cent of the words will gain new knowledge from the text and will also learn new vocabulary,” she says. “But those children who know only 85 per cent of the words will fail in two ways. They will not be able to understand the content of the text and thus won’t gain new knowledge. And they will not be able to infer the meanings of unfamiliar words from context, and thus won’t grow in vocabulary.”

“It’s not just that you’re missing a bunch of entries in a dictionary. By having a rich vocabulary, you can learn the names of the planets and terms about the solar system, and what ‘rotate’ means and what an eclipse is. You can learn those rare words because you’re gaining knowledge.”

So how should we be trying to solve the problem in schools? In England, the debate has often been focused on improving the vocabulary of “disadvantaged” children. But Fernald’s research suggests that you cannot just focus on one group in this way.

“Parents in some of the poorest families were more engaged [verbally] with their infants than parents in some of the wealthiest families,” she explains. “The important point here is that, regardless of socioeconomic status, those children whose parents provided richer verbal input learned vocabulary more quickly and showed stronger language skills.”

She adds that the extent to which schools can make up the difference is a matter of considerable debate. Fernald, though, stresses again that contextual learning of new vocabulary should be key. Simply building vocabulary by teaching pupils words from lists is unlikely to be effective in the long term, she says.

“You learn much, much better by learning a word in context,” she argues. “We need to be working with these children, reading them complex texts, not just teaching them how to decode with simple books. We have to choose books where they will learn something and integrate reading about complex topics.

“It’s their experience in learning through listening that is the best builder of vocabulary. If teachers can read complex stories to them rather than simple ones, their vocabulary will continue to grow because they will be building up conceptual knowledge. That is the key.

“If we don’t do that, we aren’t doing right by these kids.”

Zofia Niemtus is a freelance writer